Short answer: Keep unopened Novolin N in the fridge at 36-46°F (2-8°C) until the expiration date. Out of the fridge, a vial lasts 42 days up to 77°F (25°C) and a FlexPen 28 days up to 86°F (30°C). Once opened, neither goes back in the fridge. Novolin N is cloudy and must be mixed right before each dose. Do not use it if it froze. Source: Novolin N label, sections 2.1 and 16.2.
What does the Novolin N label say?
Section 16.2: “Do not expose NOVOLIN N vials and NOVOLIN N FlexPen to excessive heat or light. Do not freeze. Do not use after the expiration date.”
Novolin N US prescribing information, section 16.2, Table 2.
| Form | Unopened, refrigerated | Unopened, room temp | In use (opened), room temp |
|---|
| 10 mL multiple-dose vial | Until expiration date | 42 days up to 77°F (25°C) | 42 days up to 77°F (25°C), do not refrigerate |
| 3 mL FlexPen | Until expiration date | 28 days up to 86°F (30°C) | 28 days up to 86°F (30°C), do not refrigerate |
Section 16.2 does not repeat “do not use if it has been frozen”, but the Patient Information and Instructions for Use both say: “Do not freeze Novolin N. Do not use Novolin N if it has been frozen.”
How is Novolin N mixed before a dose?
Novolin N is a white, cloudy suspension that settles. Section 2.1 says it “must be resuspended immediately before use”, and that this is easier once the insulin has reached room temperature.
- Vial (section 2.1): “roll the vial gently in your hands in a horizontal position 10 times until the suspension appears uniformly white and cloudy. Inject immediately.” The Instructions for Use add that shaking right before drawing up a dose “may cause bubbles or froth, which could cause you to draw up the wrong dose of insulin.”
- FlexPen (section 2.1): “gently move the pen up and down 20 times so the glass ball moves from one end of the cartridge to the other until the suspension appears uniformly white and cloudy.” The Instructions for Use say at least ten times for every following injection, and to use a new pen if fewer than 12 units are left, so the rest mixes evenly.
- Do not use it if it looks discolored or has particles, or if the white deposit in a vial has become lumpy or granular.
The FlexPen carton prints “Shake carefully before using.” The Instructions for Use describe moving the pen up and down, and for vials they warn that shaking can cause bubbles. Follow the Instructions for Use steps.
What do the Patient Information and Instructions for Use add?
- Vials: “Keep Novolin N away from heat or light.” Unopened vials stored at room temperature up to 77°F (25°C) are thrown away after 42 days.
- Opened vials: “Opened Novolin N vials can be stored at room temperature up to 77°F (25°C). Do not refrigerate.” Throw them away after 42 days, even if insulin is left.
- FlexPen in use: “Store the Novolin N FlexPen you are currently using out of the refrigerator at room temperature up to 86°F (30°C) for up to 28 days.” Store it without the needle attached. Unused pens stored at room temperature are thrown away after 28 days.
- The FlexPen carton adds: keep unopened pens refrigerated “in the original carton to protect from light until expiration date or first use.”
Novolin N may be mixed in the same syringe only with Novolin R, drawing up the Novolin R first and injecting right away. See the Novolin N dosing schedule, Novolin N side effects, Novolin R and Humulin N, Lilly’s NPH insulin with different limits (vial 31 days, KwikPen 14 days).
How do you travel with it?
An opened Novolin N vial travels at room temperature for the rest of its 42 days, with a 77°F (25°C) limit; an in-use FlexPen goes up to 86°F (30°C) for the rest of its 28 days. Keep spares off direct contact with an ice pack, since frozen Novolin N is not used.
- TSA allows medically necessary liquids over 3.4 oz in carry-on bags; declare them at the checkpoint for inspection.
- Unused syringes and pen needles are allowed when they travel with the injectable medicine.
- Ice packs and gel packs that keep medicine cool may go through frozen, partly frozen or melted.
- Keep medicine in your carry-on, not checked luggage, where you cannot control the temperature. Do not let it touch an ice pack directly, since most labels say do not freeze.
More in the travel guide.
Quoted from the current US label on DailyMed, not personalized advice. Labels change; the leaflet in your own carton, your pharmacist and your prescriber are the final word on how to store it.